Ultra-processed foods, which account for more than half of the typical British diet, may be contributing to higher risks of cancer, diabetes and premature death, a major study suggests.
Researchers found that each additional 100g of ultra-processed food (UPF) consumed daily was associated with a 14 per cent increase in the risk of a major cardiovascular event, a 4 per cent rise in cancer risk and a 3 per cent increase in the likelihood of dying from any cause.
The category includes crisps, biscuits and sweets, as well as breakfast cereals, sliced bread and ready meals. Previous research indicates that UPFs provide about 54 per cent of the calories consumed by UK adults. That figure rises to 64 per cent among children and 68 per cent among teenagers.
And reaching 100g may require less food than many people realise.
That amount is approximately nine custard creams, two thick slices of supermarket bread, three or four chicken nuggets, or one-third of a frozen pizza.
The apparent health risks were even greater among people whose diets contained the highest proportions of ultra-processed food.
Compared with those who ate the least, the biggest consumers were about 25 per cent more likely to experience a heart attack or stroke, develop obesity, or report anxiety or depression.
They also had a 31 per cent higher risk of digestive problems and were roughly 20 per cent more likely to die prematurely.
Foods containing additives, including crisps and sweets, have faced decades of scrutiny, with numerous studies associating them with type 2 diabetes and other health conditions
The research, published in the BMJ journal Family Medicine and Community Health, combined results from 51 studies involving more than eight million people aged between 23 and 77 across North America, Europe, Asia and Oceania.
Some participants were followed for as long as 32 years, while their eating habits were recorded through questionnaires and food diaries.
The researchers examined the relationship between UPF consumption and a range of health outcomes, including high blood pressure, heart attack, stroke, cancer, diabetes, digestive disease, obesity, depression and anxiety, along with death from any cause.
Overall, the analysis identified a consistent trend: as ultra-processed food intake increased, so did the risk of several forms of ill health.
For every 10 per cent increase in the share of UPFs in a person’s diet, the risk of developing diabetes rose by 16 per cent.
The researchers concluded: “Our findings suggest reducing consumption of UPFs and replacing them with minimally processed alternatives could help prevent chronic disease and reduce the burden on health services.”
They noted that worldwide consumption of UPFs has climbed rapidly over the past 20 years, driven in part by their low cost, convenience and extensive marketing.
Scientists say several biological mechanisms could help explain the observed association between ultra-processed food and poorer health.
Many UPFs contain high levels of sugar and salt but little fibre. Emerging evidence also suggests that combinations of additives may create a “cocktail effect”, potentially altering gut bacteria, promoting inflammation and interfering with the body’s regulation of blood sugar.
Chemicals created during food processing could be another factor.
Acrylamide, for example, forms when starchy foods are cooked at high temperatures and is found in products such as crisps, chips and biscuits. The researchers said the chemical has been associated with a higher risk of heart disease.
However, the authors stressed that their findings do not prove UPFs directly cause disease.
Many of the studies relied on people accurately recalling and reporting what they ate, while other differences between those who consume large and small amounts of UPF – including income, education, exercise and alcohol consumption – could also influence their health.
Professor Gunter Kuhnle, a food scientist at the University of Reading who was not involved in the research, said: ‘Measuring food intake is notoriously difficult, as people are often not very good at remembering what they ate.
‘Estimating UPF intake is even more difficult because the definition is not always clear, with some breads for example not being ultra-processed, while supermarket loaves generally are.’
He added that a high UPF intake could be a marker of other poor dietary choices and that the study cannot prove cause and effect.
The NHS advises people to eat a balanced diet based largely on fruit and vegetables, beans, pulses, fish, eggs and other sources of protein, while choosing higher-fibre starchy carbohydrates such as wholegrain bread, pasta and rice where possible.
